Cyclic polyethers as catalyst activators in the alkalicatalyzed reaction of alkylene oxides

ABSTRACT

In the alkali-catalyzed reaction of an alkylene oxide with an active hydrogen compound, the rate of the reaction is increased by the presence of a cyclic polyether having at least four ether groups. Preferred polyethers are those consisting of 4-10 oxyethylene groups.

United States Patent 11 1 Exner et al.

1 CYCLIC POLYETHERS AS CATALYST AC'TIVATORS IN THE ALKALICATALYZED REACTION OF ALKYLENE OXIDES [75] Inventors: Jurgen H. Exner; David P. Sheetz;

Edwin C. Steiner, all of Midland,

Mich.

[73] Assignee: The Dow Chemical Company,

Midland, Mich.

[22} Filed: June 2, 1971 211 App]. No.: 149,378

[52] US. Cl...... 260/615 B, 260/209 R, 260/611 A, 260/611 B, 260/612 D, 260/612 B, 260/613 R, 260/613 D, 260/613 B, 260/615 R [51] Int. Cl. C07c 41/02 [58] Field of Search "260/615 B, 615, 611 B,

[56] References Cited UNITED STATES PATENTS 2,782,240 2/1951 Het'rer et al. 260/615 5 x HFOREIGN PATENTS OR APPLICATIONS 785,229 10/1957 Great Britain 260/615 Primary Examiner-Howard '1'. Mars Attorney-Griswold 8LBurdick and C. E. Rehberg [57] ABSTRACT In the alkali-catalyzed reaction of an alkylene oxide with an active hydrogen compound, the rate of the reaction is increased by the presence of a cyclic polyether having at least four ether groups. Preferred polyethers are those consisting of 4-10 oxyethylene groups.

7 Claims, No Drawings 1 2 CYCLIC POLYETHERS AS CATALYST Other suitable polyethers include the analogs of ACTIVATORS IN THE ALKALICATALYZED those above wherein one or more of the fused rings REACTION OF ALKYLENE OXIDES bear substituents such as methyl, ethyl,'butyl, phenyl,

and the like, in any available positions on the rings. BACKGROUND OF THE INVENTlON Many of the suitable polyethers are known and 0th- The reaction of an alkylene oxide with a compound erS can be made y known methods y Substitution of having at least one active hydrogen is commonly c mthe appropriate analogous reactants. Known methods lyzed with alkali metal base oxyalkylation catalyst, e.g., e Shown in the refe ences C ed above, in Canadian with alkali metal hydroxide, alcoholate, phenate, etc. P in Freheh 1,440,716 and in Cyclic hexamer of ethylene oxide is known as are rethe Publications of Pedersen, Chemlated monoand polybenzo and cyclohexyl cyclic 2,495 and 7,017 and 92, 386 and ethers (Pedersen, J Am, Chem, Soc 89, 2,495, 7,017 In practicing the process of the invention, the amount (1967). See @1150 Belgian Pat. No. 743,262, 1am. Pat. of polyether used y be varied y- AS little as No. 1,108,921 and 1,149,229 and Ger. Pat, application mole p rmo of at ly t a Significant No. 1,963,528, crease in the rate of reaction in some instances, though The benzo and cyclohexyl cyclic ethers disclosed by g amounts ate m effeetive- Oh the other hand, Pedersen are said to catalyze the dehydrohalogenation when the molar ratio of polyether to catalySt Substan- Of a iphat c halohydrocarbons (Crary, Canadian P tially exceeds 1:1, a trend of diminishing effect is noted No. 834,779), such that little improvement is achieved by ratios exceeding about 5:1, though in some instances it may be SUMMARY OF THE INVENTION desirable to use ratios of 10:1 or more. According to the invention, the alkali-metal base cat- The alkylene Oxides with which the p PmeeSS alyzed reaction of an alkylene oxide with an active hyy be practiced e those Oxides that are P y drogen compound is accelerated by the presence of a able y use of alkali metal base OXyalkylatioh catalystscyclic polyether containing at least four ether groups in The term alkylene as used herein ihehldes those the ring. By active hydrogen compound we mean to kylehe groups bearing inert, substituents, such as p y include the alkali metal salts of such compounds, e.g., and alkoxy p Thus; Suitable Oxides include the not only alcohols, ph l d amines b l h unsubstituted vicinal alkylene oxides, such as ethylene, responding alkali metal alcoholates, phenates and am- P py and 2,3-buty1ehe, isobutylehe ahd'l ides. Suitable polyethers include all those disclosed in Octehe Oxide, y Oxide, the y y ethers, Such as the above references, the disclosures of which are methyl, butyl l p p t y yh hereby incorporated reference and like. The li ethers are those f the f l The alkali metal base oxyalkylation catalysts with which the polyethers are effective are the alkalies that l I L effectively catalyze the polymerization of alkylene ox- LOHRCHR J ides. These include the alkali metal hydroxides, alkoxides, phenoxides and the like. While the Li, Cs, etc.,alwherein each R and R, take separately, is H, phenyl or kalies are operable, the preferred catalysts are the Na alkyl of up to about eight carbon atoms, or R and R in and K alkalies because of their ready availability, low any or all of the n units may be joined together to form 0 cost and effectiveness. The manner of using such cataa benzene or cycloalkane ring of 5 to 6 members, and lysts is well known in the art and need not be elabon is an integer 4 to 10. rated here.

The catalyst and polyether may be dissolved in wate DETAILED DESCRIPTION alcohol, glycol, phenol, or other active hydrogencon The preferred polyethers are those of the above fortaining initiator which is to be oxyalkylated, or in the mula wherein each R is H or lower alkyl, i.e,, of 1-4 alkylene oxide to be used in the reaction, or in an carbon atoms, each R is H and n is 4-6. added inert solvent. Among the latter are tertiary alco- The table below lists a variety of suitable polyethers, hols, aliphatic ethers, hydrocarbons, etc. thus illustrating the scope of the invention. In the table, Examples of commonly used active hydrogenbearing the tabulated elements refer to the above formula. The initiators include the alkanols, such as methanol, ethatable shows the substituents, if any, on each of the n nol, butanol, octanol, sec.-amyl alcohol and 2- units in the cyclic polyether. octadecanol; the alkenols such as ally] alcohol, u'n

TABLE I.-POLYETHERS n v Unit number n R R' R R R R R R R R R R R R R R R R R R 4 H H H H H II II H 5 II Me II Me 1-! Me II Me ll Me 6 Me Mr: \lc Me Me Me Me Me Me Me a Mo 8 H Et II Et II Et H Et II Et I-I Et 6 H H 11 I-I II d: H 4 H 001: II Oct 11 Oct H 10 II H H H H ll II 6 (132) H H 11 ll 4 (132) (Hz) (B2) 6 (Hz) 11 H (Bz) B (132) H Me II Me 6 (Cy-6) H H H II 6 (Cy-6) Bu II Bu H Y- W y-5) 6 y- W Y- Abbreviations: Me for methyl, Et for ethyl, Get for octyl, a for phenyl, (B2) for benzene (parentheses indicate that R and R are joined together to form the indicated group), Cy-6 lor cyclohexyl and Cy- 5 for cyclopentyl.

such as benzyl phenethyl and cinnamyl alcohols; glycols, such as ethylene, diethylene, tripropylene, trithe alcohol, methyl monoether of triethylene glycol,

were added to the reaction mixture. The alkylene oxide was EO. Results are shown in Table 111.

TABLE III Alkoxlde Cyclic polycther E Alcohol Temp Rate Example Cation Conc., M. Cone, M. cone, M. Type Cone, M. const 18 Na 0. 40 0. 47 0.90 0 60 46.1 19 Na. .47 .47 1.00 0.51 til) 57.1 20 Na .51 .48 1.02 (150) .57 00 62.2 21 K .53 .46 1.08 0 2.1) 22 K .53 .40 1.09 (EO)4 .55 25 3.0 23 K .52 48 1.07 (EO) .57 25 11.4

methylene, 1,2- and 2,3-butylene and 1,2-octylene glycols and the higher polyethylene and polypropylene glycols having up to 100 or more alkylenoxy groups and the monoethers of such glycols and polyglycols; the higher aliphatic polyols having 3-8 hydroxyl groups, such as glycerol, pentaerythritol, sorbitol, sucrose and polyvinyl alcohol; phenols and polyphenols, such as phenol, diphenol, Bisphenol-A, phenolaldehyde condensates, etc.

SPECIFIC EMBODIMENTS The practice of the invention is illustrated by the following examples.

The effect of the polyethers in accelerating the basecatalyzed reaction of alkylene oxide with an, active hydrogen compound or alkali metal salt thereof was demonstrated by a series of experimentsin which'ethylene oxide (E0) or propylene oxide (P0) was reacted with the methyl monoether of triethylene glycol, using the alkali metal salt of the latter as catalyst and diglyme as the solvent. The reaction was conducted in sealed tubes at constant temperature and the extent of reaction was measured by disappearance of alkylene oxide. The rate constants were calculated and are shown in Table 11.

TABLE II In a third series of experiments, cyclic tetramer of ethylene oxide was used to accelerate the reaction of ethylene oxide with butanol catalyzed by sodium butoxide.

To a 0.138 molar solution of sodium n-butoxide in n-butanol was added sufficient ethylene oxide to provide a concentration of about 0.5 molar of the oxide. To aliquot portions of this mixture, various amounts of the cyclic tetramer of ethylene oxide were added. All the mixtures, in closed vials, were then placed in a bath at C. Periodically, samples were withdrawn and analyzed for ethylene oxide. From these analyses, the rate constant based on disappearance of ethylene oxide was calculated. This constant, k, is compared with the constant, k obtained in the absence of the cyclic tetramer. The data are summarized in Table IV. In the table the concentration of the tetramer is expressed as moles per mole of sodium butoxide.

TABLE IV Conc.

Example Tetramer k/k 24 1.00 25 0.41 1.60 26 1.12 2.82 27 10.20 3.47

[Eileet 01 added cyclic polyether on rate 01 reaction of alkali metal alkoxldes, MO(CH2CH2O)1CH3, with alkylene oxides in diglyme as an inert solvent] Alkoxide Alkylene oxide Cyclic ether 11 Temp, Rate Cation C0nc., M. Type Cone, M. Type c0110., M C. constant b Li 0.50 E0 0. 45 0 2. 7 Li .61 E0 .46 (EO)4 0. 54 60 3.1 Na 53 E0 .49 0 60 6. 5 Na 57 E0 .54 (EO)4- .61 60 8.1 Na .49 E0 .45 (EON. .50 1 60 12. 1 Na .60 E0 .60 0 60 6. 3 Na .48 E0 .60 (PO)5 .46 60 11.0 Na .60 E0 .60 (CPO)4. .64 60 8. 7 Na .60 E0 .60 l)il)enzol n .64 60 7. 5 Na .60 E0 .60 l)icycloheX-18cr0wn-6 .64 60 14. 7 K .52 1'10 0 25 31. l K 61 E0 5H .55 38. 5 K 51 ICU 5!! 215 000 K .130 E0 0 25 20. 7 K .60 I'll) til .25 000 "(I-IO); and 1120);, are cyclic tetramer and IltXilllltl' of E0, respectively; (lO)5is cyclic ll llllllllll' 01' 10; (FPO) is eyclopentunioxide cyclic tetramer; dibenzo-ltlcrown-fi is and dieyelohex-18-crown-6 is the analogous dicyclohexano derivative.

5 Second order rate constant, 10 kM- Uindefined by d[EO]/dt=k[EO] [alkoxide].

A second series of experiments was made, similar to those of Table II except that varying concentrations of In a final series of experiments, the effect of cyclic polyethers on the rate of reaction of EO with n-butanol,

alkali metal hydroxide being the catalyst, was studied.

Results are shown in Table V.

ether having the formula TABLE v i ducting the reaction in the presence of a cyclic poly- Catalyst Cyclic polyether E0 00110., Temp, Rate Example Type Cone, M. M. Type 11 C. const.

LiOH-II2O 0. 0150 2 100 1,440 LiOH-Hg0 0.0156 2 (E0); 100 1,510 LiOH-HzO 0,0156 2 (E0); 100 2,340 NaOH .14 2.2 60 104 NaOH .1; 2.2 PO 00 471 NaOH 14 2. 2 Dicyclohcx-lS-crown-(i. 60 503 NaOH .0155 2 100 1, 740 NaOH .0155 2 (EO)4 100 3,180 NaOH .0155 '2 (EO)i. 100 13,500 NaOH .0155 2 (E0)@ 100 8,130 NaOH 0155 2 (E0)a 100 23, 200 NaOH .0155 2 (PO)4 1,820 KOH l3 2. 2 60 123 KOH .13 2.2 (P0)5 .13 00 277 KOH .13 .2 13 60 538 KOH .0150 2 0 100 1,800 44 KOII .0150 .052 100 2,800 46 KOII (1150 307 100 (i, 010

h For ldvnLlLy 0f pnlyutlmrs see footnote (0), Table II While we have described the invention in tenns of carrying out the process in the presence of cyclic polyethers, it is known that the alkali metal cations form complexes in situ with these ethers. Accordingly, such complexes can be prepared separately and then added to the reaction mixture, and such variant is intended to be included by the language in the presence of the ether.

We claim:

1. In the process wherein the reaction of an unsubstituted vicinal alkylene oxide with an active hydrogen compound which is an alkanol, alkenol, alkylene glycol, polyalkylene glycol, monoether of such glycol or polyglycol, glycerol, pentaerythritol or sorbitol is catalyzed by an alkali metal base, the improvement of conm LCHRCHR O.J

or alkyl of up to eight carbon atoms, or, in any or all of the n units, may be joined together to form a benzene or cycloalkane ring of 5 to 6 members, and n is an integer 4 to 10, the molar ratio of said ether to alkali metal base being 0.l:l.0 to 10:1.

2. The process of claim 1 wherein R is H, R is H or lower alkyl and n is 4-6.

3. The process of claim 1 wherein 0.1 to 10 moles of the polyether per mole of catalyst is used.

4. The process of claim 1 wherein the alkylene oxide is ethylene or propylene oxide.

5. The process of claim 1 wherein the alkali metal is Na or K.

6. The process of claim 5 wherein R and R are H and n is 4-6.

7. The process of claim 1 wherein the active hydrogen compound is the methyl monoether of triethylene glycol, the alkylene oxide is ethylene oxide or propylene oxide and the molar ratio of cyclic polyether to alkali metal base is 01:10 to 10:1. 

2. The process of claim 1 wherein R'' is H, R is H or lower alkyl and n is 4-6.
 3. The process of claim 1 wherein 0.1 to 10 moles of the polyether per mole of catalyst is used.
 4. The process of claim 1 wherein the alkylene oxide is ethylene or propylene oxide.
 5. The process of claim 1 wherein the alkali metal is Na or K.
 6. The process of claim 5 wherein R and R'' are H and n is 4-6.
 7. The process of claim 1 wherein the active hydrogen compound is the methyl monoether of triethylene glycol, the alkylene oxide is ethylene oxide or propylene oxide and the molar ratio of cyclic polyether to alkali metal base is 0.1:1.0 to 10:1. 